Differential rotation limiting force control apparatus for center differential

A differential rotation limiting force control apparatus for a center differential, to be mounted on a vehicle including the center differential and a differential rotation limiting device, the center differential being configured to transmit a motive force generated by a travel power source to a front wheel driving device and a rear wheel driving device and permit differential rotation between the front wheel driving device and the rear wheel driving device, the front wheel driving device being configured to drive a front wheel of the vehicle, the rear wheel driving device being configured to drive a rear wheel of the vehicle, the differential rotation limiting device being configured to generate a limiting force that limits the differential rotation, the differential rotation limiting force control apparatus comprising:

• an inwardly headed state detection processor configured to make a detection of an inwardly headed state based on i) a yaw rate of a vehicle body of the vehicle, ii) a vehicle speed and iii) a steering angle, the yaw rate being detected by a yaw rate sensor of the vehicle, the vehicle speed being detected by a vehicle speed sensor of the vehicle, the steering angle being detected by a steering sensor of the vehicle, the inwardly headed state being a state in which i) the vehicle is cornering and ii) a front side of the vehicle body is directed inwardly of cornering with respect to a vehicle's direction of travel;
• and
• a limiting force control processor configured to control the limiting force, in response to the detection of the inwardly headed state, to reduce a difference between a motive force on the rear wheel caused by an output of the travel power source and an absolute value of a braking force on the rear wheel caused by internal circulation torque of the center differential.

A differential rotation limiting force control apparatus for a center differential, to be mounted on a vehicle including the center differential and a differential rotation limiting device, the center differential being configured to transmit a motive force generated by a travel power source to a front wheel driving device and a rear wheel driving device and permit differential rotation between the front wheel driving device and the rear wheel driving device, the front wheel driving device being configured to drive a front wheel of the vehicle, the rear wheel driving device being configured to drive a rear wheel of the vehicle, the differential rotation limiting device being configured to generate a limiting force that limits the differential rotation, the differential rotation limiting force control apparatus comprising circuitry configured to:

• calculate a side-slip angle of a vehicle body of the vehicle based on i) a yaw rate of the vehicle body detected by a yaw rate sensor of the vehicle, ii) a vehicle speed detected by a vehicle speed sensor of the vehicle and iii) a steering angle detected by a steering sensor of the vehicle, the side-slip angle indicating an angle of the vehicle body relative to a vehicle's direction of travel in plan view with the vehicle viewed from above;
• make a detection of an outwardly headed state based on i) the yaw rate and ii) the slip-angle, the outwardly headed state being a state in which i) the vehicle is cornering and ii) a front side of the vehicle body is directed outwardly of cornering with respect to the vehicle's direction of travel;
• and
• control the limiting force, in response to the detection of the outwardly headed state, to reduce a difference between a motive force on the front wheel caused by an output of the travel power source and an absolute value of a braking force on the front wheel caused by internal circulation torque of the center differential.

A differential rotation limiting force control apparatus for a center differential, to be mounted on a vehicle including the center differential and a differential rotation limiting device, the center differential being configured to transmit a motive force generated by a travel power source to a front wheel driving device and a rear wheel driving device and permit differential rotation between the front wheel driving device and the rear wheel driving device, the front wheel driving device being configured to drive a front wheel of the vehicle, the rear wheel driving device being configured to drive a rear wheel of the vehicle, the differential rotation limiting device being configured to generate a limiting force that limits the differential rotation, the differential rotation limiting force control apparatus comprising circuitry configured to:

• calculate a side-slip angle of a vehicle body of the vehicle based on i) a yaw rate of the vehicle body detected by a yaw rate sensor of the vehicle, ii) a vehicle speed detected by a vehicle speed sensor of the vehicle and iii) a steering angle detected by a steering sensor of the vehicle, the slip-angle indicating an angle of the vehicle body relative to a vehicle's direction of travel in plan view with the vehicle viewed from above;
• make a detection of an inwardly headed state based on i) the yaw rate and ii) the slip-angle, the inwardly headed state being a state in which i) the vehicle is cornering and ii) a front side of the vehicle body is directed inwardly of cornering with respect to the vehicle's direction of travel with a yaw rate and a side slip angle of a vehicle body of the vehicle having different signs;
• and
• control the limiting force, in response to the detection of the inwardly headed state, to reduce a difference between a motive force on the rear wheel caused by an output of the travel power source and an absolute value of a braking force on the rear wheel caused by internal circulation torque of the center differential.